The happy ending to this story? This photo doesn't just highlight a railroad tunnel (and me). It shows a tunnel that was carved into a dolomite rock formation.
It was, for the most part, dolomite that proved to be the "waste" that ended up in mountains of "tailings" at the lead mine operation. Eventually some 29 million tons of "waste."
If you understand what pH is all about you know that the best soils for growth of crops, lawns, or flowers are those that are pH neutral - neither acidic nor alkaline. 200 years ago the concept was unheard of.
Here in Virginia, particularly on the old Tidewater plantations where tobacco was a cash crop and was planted year after year, the soil became so poor (from a lack of fertilization and from pH imbalance) that farmers abandoned the fields and moved west to find fertile ground.
It was only in the last century that the value of dolomite has been realized and developed.
Dolomite is high on the alkaline side. Soils all up and down the east coast tend toward the acidic. Especially if overfarmed.
Dolomite makes for a great balance. Thus, if you go to Walmart, Lowe's, or Home Depot, you'll find "aglime" - agricultural lime - for sale (either dolomitic or calcitic). And here in Virginia and West Virginia and Tennessee where does that dolomitic lime come from? You guessed it. Those mountains of tailings in Austinville. They're being reclaimed. Recycled.
Rocks from the Lead Mines crushed, pulverized, and bagged for your convenience.